1. Field of the Invention
The present invention is related to a method of deriving a path of contact on a face gear using a face gear having a plurality of gear teeth and a pinion gear meshing with the face gear, a method of manufacturing a face gear, a face gear and a spinning reel rotor drive device.
2. Background Art
The spinning reels are generally structured under the condition that a handle shaft and a rotor are respectively disposed about axes skew to each other. Therefore, a rotor drive mechanism includes a face gear and a pinion gear with helical gear teeth for transmitting rotation of a handle to the rotor. The face gear includes gear teeth formed by cutting a disc using a cutting tool that has the same shape as the pinion gear with the helical gear teeth. Accordingly, anglers feel that the handle is smoothly rotated (the angler's feeling with respect to the handle rotation will be hereinafter referred to as “rotational feeling”).
Japan Laid-open Patent Application Publication No. JP-A-2010-075075 describes an exemplary well-known face gear to be produced by die-forming using a die on which an original face gear produced by cutting is transferred. This realizes mass production of the face gears and reduction in production cost of the face gears.